键盘输入字符串 数字转换为 * 英文字母大写转小写 小写转大写

public static void main(String[] args) {Scanner s = new Scanner(System.in);System.out.println("请输入您想输入的字符串：");String str = s.next();StringBuffer sb = new StringBuffer();int i;for (i = 0; i <= str.length() - 1; i++) {char ch;if (str.charAt(i) >= 'a' && str.charAt(i) <= 'z') {ch = (char) (str.charAt(i) - 32);} else if (str.charAt(i) >= 'A' && str.charAt(i) <= 'Z') {ch = (char) (str.charAt(i) + 32);} else if (str.charAt(i) >= '0' && str.charAt(i) <= '9') {ch = '*';} else {ch = str.charAt(i);}sb.append(ch);}System.out.println(sb);}

运行结果

请输入您想输入的字符串：

111333LANCEmaven

******lanceMAVEN